There are at least three bands called ZAO: 1) The American Zao’s storied career was documented on the two-disc “The Lesser Lights Of Heaven” DVD and the luminaries of today’s heavy music scene are well aware of their debt to the band. Underoath and Unearth opened for Zao. Thrice and Fall Out Boy listened to Zao while growing up. As I Lay Dying invited Dan Weyandt to guest on their album Shadows Are Security (He performed guest vocals on Control Is Dead) and Matt Heafy from Trivium joined the band onstage to perform “Praise The War Machine.”